JP2008128882A - Contact probe and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact probe of a multilayer structure that moves smoothly during inspection and which is less apt to cause displacement with respect to electrode. <P>SOLUTION: The contact probe includes a tip part brought into contact with a surface to be measured; a spring part connected to the tip part; and a support part connected to the spring part and supporting the tip part and the spring part. The tip part, the spring part, and the support part are constituted so that when the support part is fixed and the tip part is pressed against the surface to be measured; the tip part is elastically deformed by the spring part while abutting against the surface to be measured; and the tip part includes a part, comprising a multilayer structure in which a plurality of plate-like bodies are laminated, wherein the plurality of laminated plate-like bodies are aligned in the direction of pressing against the surface to be measured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a contact probe used for electrical inspection by contacting an electrode of an electronic component such as a semiconductor IC chip or a liquid crystal device, and a manufacturing method thereof.

  In order to electrically inspect electronic components on which IC and LSI are mounted at high density, a probe card having a large number of contact probes is used. FIG. 6 shows a basic structure of a conventional cantilever type contact probe. FIG. 6A is a side view, and FIG. 6B is a plan view. As shown in FIG. 6, the contact probe has a tip portion 61, a spring portion 62, a support portion 63, and a wiring portion 64, and is held on the probe card by the support portion 63. In the inspection, the tip 61 of the contact probe is pressed against the electrode of the electronic component, and various data are collected from the electronic component. The tip 61 of the contact probe is sharp, breaks the oxide film formed on the surface of the electrode, and provides electrical conduction. Moreover, in order to absorb the curvature of the electronic component which is a test object, and the dispersion | variation in the height of an electrode, and to obtain a reliable contact with an electrode, it has a spring structure.

  The basic structure of a probe card for mounting a cantilever contact probe is illustrated in FIG. FIG. 7A is a perspective view, and FIG. 7B is a cross-sectional view taken along VIIB-VIIB. As shown in FIG. 7A, a large number of wirings are arranged in the radial direction on the upper surface of the probe card. FIG. 7A shows a part thereof. Further, as shown in FIG. 7B, the probe card 70 is supported in a cantilevered manner by the disc-shaped substrate 72, the needle pressing portion 74 incorporated in the substrate 72, and the needle pressing portion 74. It consists of a plurality of cantilever contact probes 76. Therefore, since the spring part of the cantilever-type contact probe is disposed horizontally along the substrate 72, the probes easily interfere with each other and are not easily integrated.

  Today, as the integration of ICs and LSIs progresses and the arrangement density of electrodes to be inspected increases, integration and miniaturization of contact probes are required. Under such circumstances, vertical contact probes are Has been developed. A conventional vertical contact probe and its mounting state are illustrated in FIG. 5 (see Patent Document 1). FIG. 5A shows the plunger 51 in contact with the electrode to be inspected, and FIG. 5B shows the spring 52. FIG. 5C shows a state where a vertical contact probe composed of a plunger 51 and a spring 52 is mounted. As shown in FIG. 5C, a bottom cover 57 provided with wiring 57 a is fixed to an insulating pin holding substrate 56 in which a large number of through holes 53 are formed, and a plunger 51 and a spring 52 are placed in the through holes 53. Then, the upper lid 55 having a hole slightly smaller than the through hole 53 is joined. This vertical contact probe has been introduced as being capable of integration with a pitch of about 80 μm. However, since the plunger (contact portion) 51 and the spring (elastic portion) 52 are separately manufactured and mounted, the contact probe Compared with the case where the whole is integrally molded, the component cost and the assembly cost are high, and miniaturization is not easy.

  As a conventional manufacturing method for integrally forming a fine contact probe, a method as shown in FIG. 4 combining lithography and electroforming has been put into practical use (see Patent Documents 2 and 3). First, as shown in FIG. 4A, a resist 42 such as polymethyl methacrylate is formed on a conductive substrate 41 such as a stainless steel substrate. Next, a mask 43 is disposed on the resist 42, and UV or X-ray 44 is irradiated through the mask 43. The mask 43 is composed of an absorbing layer 43a such as UV or X-ray 44 formed according to the shape of the contact probe and a translucent base material 43b. Therefore, when the X-ray 44 is irradiated, the resist 42 is formed by the absorbing layer 43a. Of these, only the resist 42a is exposed. For this reason, in the case of a positive resist, only 42a that has been altered by exposure (molecular chain is cut) is removed by development, and a resin mold 42b as shown in FIG. 4B is obtained.

Next, electroforming is performed, and a metal material layer 45a is deposited on the resin mold 42b as shown in FIG. 4 (c). Electroforming refers to forming a metal material layer on a conductive substrate using a metal ion solution. By performing electroforming using the conductive substrate 41 as a plating electrode, the metal material layer 45a can be deposited on the resin mold 42b. After electroforming, when a predetermined thickness is obtained by polishing or grinding, a metal structure 45 as shown in FIG. 4D is obtained. Thereafter, as shown in FIG. 4E, the resin mold is removed by etching or the like. Subsequently, when the conductive substrate 41 is removed by wet etching or the like, a contact probe made of a fine metal structure 45 as shown in FIG. However, the contact probe obtained by this method has a single-layer structure, and the tip part, the spring part, and the support part have the same thickness. Therefore, in order to suppress cracking of the electrode to be inspected, the pressure applied to the electrode is lowered. However, in order to break the oxide film on the electrode surface and obtain electrical conduction, it is necessary to sharpen the contact portion of the tip portion with the electrode by another process such as polishing.
JP 2001-21583 A JP 2001-254193 A JP 2001-316862 A

  An object of the present invention is to provide a contact probe having a thin and sharp shape in which a tip portion contacting an electrode to be inspected is not subjected to tip processing separately. It is another object of the present invention to provide a method for manufacturing a multi-layer contact probe that moves smoothly during inspection and is less likely to be displaced from an electrode.

  The contact probe of the present invention includes a tip portion that contacts the surface to be measured, a spring portion that is connected to the tip portion, and a support portion that is connected to the spring portion and supports the tip portion and the spring portion. The portion and the support portion are configured such that when the support portion is fixed and the tip portion is pressed against the surface to be measured, the tip portion is elastically deformed by the spring portion while being in contact with the surface to be measured. It has the part which consists of a multilayer structure which laminated | stacked the several plate-shaped object, and the several laminated | stacked plate-shaped body orients along the direction pressed against a to-be-measured surface.

The multilayer structure preferably has an aspect in which the width w ₂ of the plate-like body laminated at the peripheral portion is narrower than the width w ₁ of the plate-like body laminated at the central portion. Further, it is preferable that the distal end portion further has an abutting portion that directly contacts the surface to be measured at the distal end, and the abutting portion is formed of a single layer plate-like structure. Furthermore, the present invention is particularly effective in a vertical probe in which a tip portion, a spring portion, and a support portion are linearly arranged.

  The contact probe manufacturing method of the present invention is the above-described contact probe manufacturing method, a step of forming a resin mold by lithography, and a step of forming a metal material layer on the resin mold by electroforming on a conductive substrate. And a step of flattening by polishing or grinding, a step of forming a resin mold by lithography on the plate layer of the first layer, and a step of forming a resin mold A plate-shaped body of the first layer is formed by performing a plate-like body forming step including a step of forming a metal material layer by electroforming and a step of flattening by polishing or grinding once or repeatedly. It is characterized by comprising a step of laminating a plate-like body of the second and subsequent layers thereon, a step of removing the resin mold, and a step of removing the conductive substrate.

  In this manufacturing method, the conductive substrate is preferably a metal substrate having a coating layer made of Ti, Cu, or Al. An embodiment in which such a conductive substrate is used to remove the substrate by etching the coat layer, or an embodiment in which the substrate is removed by mechanically peeling off the coat layer as a boundary is preferable.

  A contact probe having a thin and sharp tip can be provided without subjecting the tip to processing separately. In addition, it is possible to provide a contact probe that moves smoothly during inspection and is less likely to be displaced from the electrode.

(Contact probe)
A perspective view of a contact probe of the present invention is illustrated in FIG. As shown in FIG. 1, the contact probe of the present invention includes a tip 1 that contacts the surface to be measured, a spring 2 connected to the tip 1, and a tip 1 and a spring 2 connected to the spring 2. The tip 1, the spring 2, and the support 3 fix the support 3 and press the tip 1 against the surface to be measured. The spring portion 2 is elastically deformed while being in contact with the spring. The tip portion 1 has a portion made of a multilayer structure in which a plurality of plate-like bodies 1a, 1b, and 1c are laminated, and the direction in which the plurality of laminated plate-like bodies press against the measurement surface (indicated by arrows in FIG. 1). Direction). FIG. 1 illustrates a vertical contact probe in which a tip portion 1, a spring portion 2, and a support portion 3 are arranged in a straight line.

  A cross-sectional view of a probe card for mounting a vertical contact probe is illustrated in FIG. As shown in FIG. 2, a plurality of guide holes 22 are formed in the insulating substrate 21 of the probe card in accordance with the arrangement pitch of the electrodes 25 in the circuit 24 to be inspected, and the contact probe 20 is formed in each guide hole 22. Is inserted. The tip 20 a of the contact probe 20 protrudes from the surface of the insulating substrate 21 that faces the substrate to be inspected 24. A flexible printed circuit (FPC) 23 or the like is disposed as a lead wire on the surface of the insulating substrate 21 opposite to the substrate to be inspected 24, and is connected to the support portion 20 b of the contact probe 20. Fix it. The present invention can be applied to a vertical contact probe, and the vertical contact probe is mounted on the probe card substrate by placing it vertically and linearly and inserting it into a guide hole. Compared with cantilever contact probes, high-density mounting is easy. In addition, the vertical contact probe is advantageous in that it has high resistance to high frequencies and a high degree of freedom in the needle stand layout.

FIG. 2B shows a cross-sectional view of one tip when the tip 20a is cut by IIB-IIB in FIG. Since the tip of the contact probe of the present invention has a multilayer structure, in the case of a three-stage structure as shown in FIG. 2B, there are eight contacts with the inner wall 22a of the guide hole. On the other hand, in the case of the single layer structure shown in FIG. 2C, there are only four contacts with the inner wall 22a of the guide hole. Therefore, since the contact probe of the present invention has a large number of contacts with the inner wall of the guide hole, when the tip is pressed against the electrode to be inspected, the tip can slide smoothly in the guide hole. it can. Further, since the number of contacts with the inner wall of the guide hole is large, even when the diameter of the guide hole is larger than the thickness of the tip portion, the contact probe is hardly displaced at the time of contact with the electrode. From this point of view, as shown in FIG. 2 (b), the multilayer structure at the tip has a width w ₁ of the plate-like body laminated at the peripheral portion as compared with the width w ₁ of the plate-like body laminated at the central portion. _A mode in which ₂ is narrow is preferred.

  When a contact probe having a single layer structure is formed by lithography and electroforming, the tip portion, the spring portion, and the support portion have the same thickness as described above. Therefore, in order to break the oxide film on the electrode surface and obtain electrical continuity while reducing the pressing pressure to the electrode in order to suppress cracking of the electrode to be inspected, the contact portion with the electrode at the tip portion is polished, etc. It is necessary to sharpen by another process. The tip of the contact probe of the present invention has a portion made of a multilayer structure, and polishing is achieved by making the contact portion that directly contacts the surface to be measured at the tip of the tip into a single-layer plate structure. It is useful in that it can be formed into a thin and sharp shape without using another process such as.

(Contact probe manufacturing method)
The contact probe manufacturing method according to the present invention is a method for manufacturing the above-described contact probe. After the first layer plate is formed by lithography and electroforming, the first method is similarly performed by lithography and electroforming. This is a method of laminating one or two or more layers on a layered plate, and then removing the resin mold and the conductive substrate. By this method, a contact probe having a multilayer structure can be easily manufactured, and the number of stacked plate-like bodies can be changed among the tip portion, the spring portion, and the support portion. For this reason, for example, only the contact portion at the tip portion has a thin and sharp single-layer structure, and the number of stacked plate-like bodies can be increased in the spring portion and the support portion, so that the elastic force and the mechanical strength can be increased.

  Furthermore, since it is manufactured by lithography and electroforming, the contact portion can be freely formed, and a contact probe with an easy assembly shape can be provided. On the other hand, the tip portion, the spring portion, and the support portion can be integrally formed with high accuracy of ± 1 μm, so that the number of components can be reduced, and the component cost and assembly cost can be reduced. Further, the contact probe of the present invention has a portion composed of a multilayer structure in which a plurality of plate-like bodies are laminated, and the laminated plate-like bodies are oriented along the direction of pressing against the surface to be measured. It can be easily manufactured by lithography and electroforming.

  A method for manufacturing the contact probe of the present invention is illustrated in FIG. First, a first layer plate-like body is formed. The method for forming the first layer plate-shaped body includes a step of forming a resin mold by lithography, a step of forming a metal material layer on the resin mold by electroforming on a conductive substrate, and flattening by polishing or grinding And a step of performing. In the step of forming a resin mold by lithography, a resist 33 is formed on a conductive substrate 36 as shown in FIG. For example, a metal substrate made of Cu, Ni, stainless steel, or the like can be used as the conductive substrate. Alternatively, a Si substrate on which a metal such as Ti or Cr is sputtered can be used. As the resist, a resin mainly composed of polymethacrylate such as polymethyl methacrylate (PMMA) or a chemically amplified resin sensitive to ultraviolet rays (UV) or X-rays is used. The thickness of the resist can be arbitrarily set according to the size of the structure to be formed, and is, for example, 40 μm to 500 μm.

  Next, a mask 34 is placed on the resist 33, and UV or X-rays 35 are irradiated through the mask 34. When a structure having a thickness exceeding 100 μm and having a high aspect ratio is required, or when a highly accurate structure of about ± 2 μm is required, X-rays having a wavelength shorter than UV (wavelength: 200 nm) (wavelength: 0 .4 nm) is preferred. Further, it is more preferable to use synchrotron radiation X-ray (hereinafter referred to as “SR”) having high directivity among X-rays. The LIGA method using SR enables deep lithography, and can produce a large number of structures having a thickness of several hundreds of micrometers with high accuracy on the order of microns. On the other hand, when UV is used, a merit can be pursued in terms of cost.

  The mask 34 includes an absorption layer 34a such as UV or X-ray 35 formed according to the shape of the structure to be manufactured, and a translucent substrate 34b. As the translucent substrate 34b, silicon nitride, silicon, diamond, titanium, or the like is used for the X-ray mask, and quartz glass or the like is used for the UV mask. In the case of an X-ray mask, the absorbing layer 34a is made of heavy metal such as gold, tungsten, or tantalum or a compound thereof, and in the case of a UV mask, chromium or the like is used. In the case of using a positive resist, when the X-ray 35 or UV is irradiated, only the resist 33a of the resist 33 is exposed and deteriorated by the absorbing layer 34a, so that the resist 33a is removed by development, as shown in FIG. Thus, the resin mold 33b is obtained. On the other hand, when a negative resist is used, the exposed portion remains and the non-exposed portion is removed. Therefore, a mask pattern opposite to that of the positive resist is used.

  Next, as shown in FIG. 3C, on the conductive substrate 36, a metal material layer 31a is formed on the resin mold 33b by electroforming, and is flattened by polishing or grinding, for example, a thickness of 30 μm to 200 μm. To a plate-like body. The material of the metal material layer is preferably Ni or Ni-based alloy when the contact probe to be manufactured requires high toughness and hardness, and Ni or Ni-based alloy is also preferable in that it is suitable for manufacturing by the LIGA method. . As the Ni-based alloy, NiMn, NiFe, NiCo, NiW, and NiPd are preferable. Among Ni-based alloys, Ni-Mn is preferable when the contact probe to be manufactured requires high heat resistance. The content is more preferably 3% by mass or less. On the other hand, when electrical characteristics are required, Cu or a Cu-based alloy is preferable, and Cu and a Cu-based alloy are also suitable for production by the LIGA method. Examples of the Cu-based alloy include Cu—Sn and Cu—Zn. In the present specification, the M-based alloy refers to an alloy containing 40% by mass or more of the metal element M. Of the tip, the contact portion that directly contacts the surface to be measured is excellent in electrical conductivity, has low contact resistance, is not easily worn, and has high hardness and melting point, Pt, Ir, Ni-Pd, Pd -Co or Rh is preferred.

  In this way, after the first layer plate is formed, the second and subsequent plate members are laminated on the first layer plate. A method for forming a plate-like body after the second layer includes a step of forming a resin mold by lithography, a step of forming a metal material layer on the resin die by electroforming, and a step of flattening by polishing or grinding. By the contact probe to be manufactured, the plate-like body forming process for the second and subsequent layers is performed only once to obtain a two-layer structure, and it is repeated a plurality of times to obtain a structure having three or more layers. .

As shown in FIG. 3 (h), when forming a metal material layer 31b wider than the metal material layer 31a, a mask layer 37 is formed to protect the resin mold 33b (FIG. 3 (d)). ). The mask layer 37 is preferably made of Al, SiO ₂ or the like, and the thickness is preferably 0.05 μm to 0.3 μm. Thereafter, as in FIG. 3A, after forming a resist, irradiation with UV or the like is performed by lithography (FIG. 3E), and development is performed to form a resin mold 33c (FIG. 3F). Thereafter, as shown in FIG. 3G, the mask layer 37a in the pores of the resin mold 33c is removed by etching. The mask layer 37a can be etched by plasma generated by RIE (Reactive Ion Etching) or ECR (Electron Cyclotron Reasonance) excitation using Cl ₂ , CF ₄ , F ₂ or the like. As shown in FIG. 3 (f), since the resin mold 33c is formed on the mask layer, the resin mold 33c functions as a mask and the mask layer 37a is selectively etched during etching such as RIE. (FIG. 3 (g)).

  Next, as shown in FIG. 3H, the metal material layer 31b is formed on the resin mold 33c by electroforming on the metal material layer 31a, and is flattened by polishing or grinding. When a contact probe having a two-layer structure is required, the resin molds 33b and 33c and the mask layer 37b are then removed by wet etching or plasma etching, and then removed by wet etching using acid or alkali or mechanically. Then, the substrate 36 is removed to obtain a target contact probe.

  FIG. 3 shows an example of manufacturing a contact probe having a three-layer structure. As shown in FIG. 3I, a resin mold 33d is formed by lithography (FIG. 3J). Next, as shown in FIG. 3 (k), a metal material layer 31c is formed on the resin mold 33d by electroforming, and is flattened by polishing or grinding. Next, as shown in FIG. 3 (l), the resin molds 33b, 33c, 33d and the mask layer 37b are removed, and as shown in FIG. 3 (m), the substrate 36 is removed. can get. When a metal substrate having a coating layer made of Ti, Cu, or Al is used, the substrate can be easily removed by etching the coating layer on the substrate, and mechanically with the coating layer on the substrate as a boundary. The substrate can be easily removed by peeling. The thickness of the coat layer is preferably 0.1 μm to 2 μm.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  It is possible to provide a contact probe having a multilayer structure that moves smoothly during inspection and hardly causes displacement with respect to the electrodes.

It is a perspective view which illustrates the contact probe of this invention. It is sectional drawing of the probe card which mounts a vertical type contact probe. It is process drawing which shows the manufacturing method of the contact probe of this invention. It is process drawing which shows the manufacturing method of the conventional contact probe. It is sectional drawing which illustrates the conventional vertical contact probe and its mounting state. It is a schematic diagram which shows the basic structure of the conventional cantilever type | mold contact probe. It is a schematic diagram which shows the basic structure of the probe card which mounts a cantilever type contact probe.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Tip part, 1a, 1b, 1c Plate body, 2 Spring part, 3 Support part, 31a, 31b, 31c Metal material layer, 33b, 33c, 33d Resin type, 34 Mask, 36 Substrate.

Claims (8)

  A tip portion that contacts the surface to be measured, a spring portion connected to the tip portion, and a support portion connected to the spring portion and supporting the tip portion and the spring portion, the tip portion and the spring portion being supported The portion is configured such that when the support portion is fixed and the tip portion is pressed against the surface to be measured, the tip portion is elastically deformed by the spring portion while being in contact with the surface to be measured. A contact probe having a portion made of a multilayer structure in which plate-like bodies are laminated, and oriented in a direction in which the laminated plate-like bodies are pressed against the surface to be measured. _2. The contact probe according to claim 1, wherein the multilayer structure has a width w ₂ of a plate-like body laminated at a peripheral portion thereof is narrower than a width w ₁ of a plate-like body laminated at a central portion.   The contact probe according to claim 1, wherein the tip further includes a contact portion that directly contacts the measurement surface at the tip, and the contact portion is formed of a single-layered plate-like structure.   The contact probe according to claim 1, wherein the contact probe is a vertical probe in which a tip portion, a spring portion, and a support portion are linearly arranged. It is a manufacturing method of the contact probe according to claim 1,
Forming a resin mold by lithography;
Forming a metal material layer on the conductive mold by electroforming on a conductive substrate;
Forming a first layer plate-like body comprising a step of flattening by polishing or grinding;
Forming a resin mold by lithography on the plate-like body;
Forming a metal material layer on the resin mold by electroforming;
A step of forming a plate-like body comprising a step of flattening by polishing or grinding, or a step of repeatedly performing a plurality of times, and laminating the plate-like body on the plate-like body of the first layer; ,
Removing the resin mold;
And a step of removing the conductive substrate.   The method of manufacturing a contact probe according to claim 5, wherein the conductive substrate is a metal substrate having a coating layer made of Ti, Cu, or Al.   The method of manufacturing a contact probe according to claim 6, wherein the substrate is removed by etching the coat layer on the conductive substrate.   The method of manufacturing a contact probe according to claim 6, wherein the substrate is removed by mechanically peeling the coating layer on the conductive substrate.

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